Air-circulating device for refrigerator cars



F. E. GREENE AIR CIRCULATINQDEVICE FOR REFRIGERATOR CARS July 31, 1928.

Filed April 27, 1927 IN VEN TOR. FRED E. QRELNE.

BY 1W4 MM ATTORNEYS.

Patented July '31, 1928.

UNITED STATES PATENT OFFICE.

FRED E. GREENE, OE BERKELEY, CALIFORNIA, ASSIGNOR TO A. B.- HUMPHREY COM- AIR-OIRCULATIN G DEVICE PANY, OF ESCALON, CALIFORNIA.

won" REFRIGERATOR cars.

A CORPORATION OF CALIFORNIA Applieationnled-April 27, 1927. Serial No. 186,894.

This invention relates to refrigerator cars and especially to means whereby a thermosiphon circulation of air may be promoted and maintained through the fruit and the ice bunkers while the car is in transit.

Since the origin of refrigerator cars, a

' number of attempts have been made to maintain uniform temperature and adequate refrigeration but without material success. Thousands of dollars have been paid by the carriers to the shippers usin refrigerator cars due to the inability of't e carriers to maintain the commodity at a sufliciently low temperature to guarantee delivery to the market in good condition. Refrigerator cars ordinarily contain an ice bunker at each end and the fruit or other commodity packed in the car intermediate the bunkers. Sufficient ice to cool the .commodity in the storage compartment is available in the bunkers but .as no means are provided for maintaining the air in circulation through the bunkers and the commodity, comparatively poor and inefiicient refrigeration is the result.

It is ordinarily thought that more or less circulation of air is maintained by thermosiphon action. Actual experience, however, has proven that comparatively little, if any," circulation of air takes place as the air cooled by the ice in the bunkers tends to settle in' a layer at a rather definite-elevation in the lower portion of the car. In fact the helght of cool air above the floor has been so definitely determined, that the lugs or boxes containing the fruit or other commodlties being transported are seldom stacked above a definite height as spoilage of the commod1t w1ll otherwise take place and it has accor mgly been common practice to sell the top tlers of fruit separately.

Due to the frequent spoilage of shipments both carriersand shippers have agreed upon standard heights of loading and bracing to secure the best results in transportation across the country, i; e., the load is stacked just so high and is divided into two sections to form a central air passage between the loads, to provide space for a suitable form of bracing which secures the loads against shifting and damage; and furthermore to permit such circulation of air as may take place. I

The object of the present invention is to promote and insure thermosiphon circulation of air through the bunkers and the commodity being transported. The invention is shown by way of illustration inthe accom- -panying drawings in which:

F 1g. 1 is a central vertical longitudinal section of a'standard form of refrigerator car.

Fig. 2 is a cross-section of the refrigerator car.

Referring to the drawings in detail and particularly Fig. 1, A-indicates in general central passage 10 is thus formed between the two sections and this passage is employed to promote thermosiphon circulation of the air and also to provide space fora standard form of bracing such as generally indicated atG. It might also be stated that the load which in this instance is rep-resented by the stacks of lug boxes indicated at 8 and 9 is supported by a false or elevated floor 11 which is constructed of heavy slats. The false floor provided forms a bottom air passage 12 extending. from end to end of the storage compartment and this passage is in communicationv with the lower ends of the ice bunkers through screened openings 13. The upper ends of the bunkers are also provided with screened openings such as indi: osted at 14 and as previously stated, it is ing or refrigerat-ionof the commodity being.

shipped, this being best proven by the fact that the lug boxes can only be stacked to a definite height as actual experience has proven that if the lug boxes are stacked above a definite height, the fruit or commodity disposed above that height is almost certain to spoil.

In other words, the cold air settles in the lower portion of the storage compartment and does not rise above a definite height and it is for this reason that ithas positively been determined that comparatively little, if any, thermosiphon circulation takes place. y

In the present instance,. means are provided for promoting and in fact insuring thermosiphon circulation of air. This is accomplished as follows:

- necessary to lower a pair of plates such as indicated at 15 'and'16 down on top of the load. These plates have a length substantially the same as that of the stacks of lug boxes and they are suificiently wide to extend from one side wall to the other as shown in Fig. 2. One end of each plate may rest or be entirely supported by the lug boxes as indicated at 17 while the opposite end of each plate is preferably supported by extensive folding legs such as indicated at 18. These legs support the respective plates in an inclined position. After the. plates have been lowered and placed IDYPOSI- tion as shown in Fig. 1, it is only necessary toclose 'andseal the doors of the car and the car is ready for shipment. The moment the doors have been closed, the air in the bunkers is cooled by the ice and as such Wlll. settle downwardly and discharge through the openings 13 into the passage 12 which is formed below the false floor 11. The air gradually rises upwardly between the slots and the lug boxes and as such cools the fruit. The air is,'of course, raised in temp erature by the fruit which is comparatively warm and the increase in temperature will cause theair to rise upwardly in under the tion in the upper en plates 15 and as these are positioned on an incline, the air will flow towards the central passage 10 and will then enter the upper portion of the car as shown b the arrows.

The cool air settling in the unkers will,

of course, create a s11 htly evacuated condids of the bunkers and the warm or IlSll'lg air is thus drawninto the upper ends of the bunkers and thermosiphon circulation of air is started. -This course, immediate circulation will be continuously maintained as long as there is a diiference'of temperature between the ice and the commodity being shipped. When an equalized temperature is o tained, circulation will, of course, cease but any change in temperature will, of

y start circulation and efiicient refrigeration as far as the commodity is concerned is insured. When the turned as empties. The means employed for securing the plates in under the ceiling is nothing more or-less than ordinary lugs such as indicated at 20 and 21. The lugs 20 are stationary and the ends 17 of the plates are inserted between the ceiling and the lugs 20. The lugs 21 are pivoted as indicated at 22. They are swung to assume a reverse position to that shown in full lines in Fig. 1 when the ends 17 of the plates are lifted into engagement with the lugs 20. The opposite ends of the plates are then raised up into engagement with the ceiling and the lugs 21 are then swung or reversed on their pivots and as such will swing in under the plates and secure and support the same. The plates 15 and 16 can in thls manner be conveniently handled, and stored and as they are placed in the position flush with the ceiling, they will not interfere with the storage capacity of the car if freight is handled when the car is returned. The legs 18 are swung about their pivots to lie parallel with the plates when they are in their reverse position and as such will not interfere with the freight or consume extra space, the legs 18 being held in their extended position when the plates are lowered as shown in Fig. l by ordinary braces such as shown at 18.

Actual experience has, first, determined that uniform circulation of air is maintained in an. upward direction between and through the lug boxes and the central passage 10; secondly, it has been determined that actual thermosiphon circulation takes place; and third, that the lug boxes or commodity being transported may be stacked to a greater height due to the circulation maintained and due to the fact that the comparatively cool air passes over the upper layers of the lug boxes before it can enter the-central passage 10' and return to the upper ends of the bunkers; fourth, that the commodity is received at its destination in a better condition; and fifth, that greater loads may be the several parts employed may be such as the manufacturer ma dictate or varying conditions or uses may emand. I

Having thus described my invention, what I claim and desire to secure by Letters Patent is 1. In a refrigerator car having ice bunkers at opposite ends and an intermediate storage compartment in which a perishable commodity is loaded in two stacks and braced between the stacks, a portable apparatus for promoting and maintaining a thermosiphon circulation of air through the bunkers and the commodity, said apparatus comprising a cover plate for each stack, said plates having a wldth substantially equal to the width of the car and having lengths substantially equal to that of each stack, the ends of the plates which are adjacent the bunkersbeing adapted to be supported by the commodity and means for supporting the opposite ends of the plates in an ele:

vated position with relation to the commodity and means for supporting and securing the plates in under the ceiling of the car.

, 2. In a refrigerator car having ice bunkers at opposite ends with inlet and outlet openings In each bunker, said inlet openings being adjacent. the ceiling of the car and the outlet openings adjacent the floor and an intermediate storage compartment in which bunkers and means for securing said cover members 1n the mchned position as deupwardly through scribed to cause air rising towards the point the commodity to trave adjacent the center of the car and then to 7 travel outwardly in under the ceiling of the car towards the inlet openings of the bunkers, then to settle downwardly through the ice in the bunkers and finally to return to the commodity at a point below the commodity.

FRED E. GREENE. 

